Electric control apparatus



`lam. 23, 1945. H. F. ELLIOTT ELECTRIC CONTROL APPARATUS 2 Sheets-Sheet 1 Original Filed Dec. 3, 1940 /H W l u"111111111llfllllllll/IA Jan. 23, 1945. H. F. ELLIOTT 2,367,763

' ELECTRIC CONTROL APPARATUS Original Filed Dec. 3, 1940 2 Sheeis-Sheet 2 Patented Jan. 23, 1945 ELECTRIC CONTROL APPARATUS Harold F. Elliott, Belmont, Mass.

Original application December 3, 1940, Serial No. 368,334. Divided and this application October 17, 1942, Serial No. 462,357

19 Claims.

My vinvention relates in general to control apparatus and more in particular to electric control apparatus employed in tuning a radio receiver to a plurality of predetermined signal frequencies. This application is a division of my application Serial #68,334 filed December 3, 1940, now Patent No. 2,299,082.

Many electric tuners for radio receivers have been developed in recent years and a large number of these devices have been utilized commercially. Although some of these commercial devices operate in a fairly satisfactory manner, they are generally all complicated and expensive and so large that they take up a considerable amount of space in the radio receiver apparatus to which they are applied. Because of this bulky and complicated structure their initial cost increases the overall cost of the complete radio receiver to which the tuner is adapted beyond the popular price class so as to appreciably limit the sales thereof. In addition, these prior tuners operate relatively slowly and as a result are not attractive to the operator.

It is an object of my invention, therefore, to provide an improved electrically operated control apparatus Which can be readily applied to `many types of controllable mechanism including automobile radio receivers and radio receivers for home use.

A further object of my invention is to pro` vide a compact, simple, rugged and inexpensive electrically operated control apparatus which is comprised of but a few number of easily machined and assembled parts requiring a minimum of servicing and adjusting attention. A

A still further object is to provided electric control apparatus which operates very quickly and positively and which can be easily and simply adjusted to various predetermined control positions without the use of special tools or the like.

One of the features of my invention is the provision of electric control apparatus in a preassembled unit which can be completely assembled and tested under operating conditions before it is ever assembled into the structure with which it is to be used.

Another feature of my invention is the pro- Yet another feature of my invention is found in the provision of a rotary control unit having magnetically operated pivoted latches acting with control rings in the complete control operation, in which the latches and associated magnet structures are angularly spaced about the control unit and substantially within the peripheral confines thereof whereby to provide a compact and efficiently operable unit.

Yet another feature of my invention is found in the provision of a tuning unit which includes frequency changing means adapted for reversed operation by a uni-directional rotating control shaft, in which the frequency changing means is rotated from a closed position to an open star*- 1 ing position by about a quarter revolution of the control shaft. vThe control shaft is in operative association with a switch which functions to turn the receiver on during this period of condenser rotation. This provides a simple and inexpensive means for automatically turning the' set off and on during a tuning operation whereby to save the cost of a power relay.

A still further feature of my invention is found in the provision of a rotary control unit having magnetically operated pivoted latches acting with angularly adjustable control rings in the complete control operation, in which each control ring and a corresponding hub portion thereof are adapted to be formed from a single piece of sheet metal, and stacked in a side by side relation axially of the control unit so as to occupy a minimum of space.

Other objects, features, and advantages of my invention will be apparent from the following description taken withthe drawings in which:

Fig. 1 is a longitudinal sectional view of my complete control device in a preassembled unit;

Fig. 2 is a view as seen along the line 2-2 in Fig. 1 with parts thereof removed for the pur'- pose of clarity;

Fig. 3 is a sectional view as seen along the' which includes resonant frequency changing structure such as a variable condenser mounted on the frame, and a rotary control assembly angularly adjustably supported on a rotary shaft journaled in the frame and operatively connected with the resonant frequency changing structure of the complete unit. Control rings in the control assembly are normally frictionally held against rotation relative to their supporting hub and rotary shaft, but the friction can be removed and the rings individually and independently rotated relative to the hub to a position corresponding to a predetermined signal frequency. With the control rings then frictionalily retained against rotation, the control assembly and the resonant frequency changing structure therewith are rotated by suitable driving means, such as an electric motor through the various predetermined tuning positions where each control ring, as it is selected for a tuning operation, is stopped mechanically by a pivoted latch riding on the circumference of the control ring. Each pivoted latch is selectively brought into engagement with a corresponding control ring upon pushing a control loutton or otherwise closing an operating switch and circuit to energize a solenoid therefor. rIhe energizing circuit can be closed at the radio receiver or from a remote position. Rotation of the control ring assembly by the electric motor continues until the latch engages a recess e in the selected control, which has been previously adjusted to correspond in position to a desired signal frequency. The button switch or some other operating switch is held closed during this entire tuning operation and when released at the stop position for the control ring,

opens the driving motor and solenoid circuits.

With reference to the drawings the tuner of my invention is shown in Fig. 1 as including a frame structure having side plates 403 and 404 with a` motor 40| mounted therebetween on supporting rods or bars 406. The motor 401 is of uni-directional type and is operable with alternating current to drive a control ring assembly 402 in one direction of rotation. The uni-directional rota-fv a variable condenser or other type of tuning means requiring change o f direction of motion in its operation. The motor is operatively connected through a gear train 401 with the ring assembly 402, the reduction gears 409 and 4H being mounted on a manual tuning shaft 4l2 which is rotatably mounted in the side plates 403 and 404. The ring assembly 402 is mounted on an enlarged portion 4I3 of a control shaft 4l4 which is likewise rotatably mounted in the side plates 403 and 404 (Figs. l and 3).

Assembly 402 is comprised of a plurality of control rings 4l6, six of which are indicated, with each ring having a separate hub member 4H (Fig. 6). The rings are of a uniform diameter with a notch or recess 408 being provided in the periphery thereof. Each hub member is formed with radially extending arms 410, 'the ends of which are of an arcuate contour corresponding to the inner diameter of the control ring 4|B, so that the ring is centered about the hub member and rotatable relative thereto. It is contemplated that the hub portions and control rings be metal stampings and preferably hardened to increase their service life. As is clearly apparent from Fig. 6 the cost of manufacturing a hub and control assembly can be appreciably reduced by stamping the parts from a single piece of sheet metal either in the same or separate stamping operations. Each ring and hub assembly is separated by a flat stamped out ber washer 4I8 having a diameter greater than the diameter of the control rings 4|6. Thus the separators 4| 8 provide a series of grooves on the peripheral surface of the ring assembly 402, with each groove serving to guide the travel of a latch 424 relative to its corresponding ring 4 I 6, as will be explained.

The hub members 4|1 and the separating washers M8 are stacked on the portion 4|3 and secured to the face of gear member 4 l 9 by screws 4l5 or the like, which extend through suitable apertures formed in each of the hub members 4I'1 and washers 4I8. Gear member 4l9 is rigidly secured to the control shaft 4I4 so that the washers and hub members are likewise fixed relative to the shaft 4|4, the control rings 4I6 being rotatable relative to the control shaft by virtue of their free rotation about their corresponding hub members. Although the discs or washers 4 I8 positively separate the control rings 4IB, they do permit a slight axial movement of the rings so as to permit the control ring assembly to open up enough to permit an angular adjustment of each control ring relative to the corresponding hub member 4Il, and hence relative to the rotary control shaft 4I4. This opening up of the control ring assembly is accomplished by the axial exing movement of that portion of a separator member or disc 4l8 intermediate adjacent control rings 4 I 6.

Thus with the control ring assembly 402 in an unclamped position for adjusting purposes, as will be later explained, this flexing action provides for the frictional holding of a control ring in an adjusted position and the independent adjustment of the other control rings. By virtue of the flat construction of each control ring and hub assembly and the at form of the separating discs 4I8, the control ringassembly 402 is of a minimum length axially of the control shaft 4l3.

In the operation of the control apparatus and' after the control rings 4I6 are each set to a predetermined adjusted position with reference to the shaft 4I4, as will be explained, the rings 4I6 are compressed axially as an assembly and frictionally retained against movement relative to the gear 4I9 and hence the shaft 4|4 by a friction unit 42 l` which is mounted about the control shaft 4|4. Unit 42| is of substantially sleeve form with an annularly extending flange portion 422 provided at one end thereof. The flange portion 422 is of a diameter substantially equal lto that of the control rings AIS and has an annular rim or edge 423 (Fig. 3) on the face portion thereof adapted to engage and axially press the control rings, and the portions of the separating discs therebetween, together against the gear member 4l9 on movement of the friction unit toward the right as viewed in Figs. l and 3. The face portion of the flange within the rim is axially spaced from the immediately adjacent ring hub 4H so as to be out Of engagement therewith, suitable apertures being formed in the flange to permit the screws 4l5 to extend therethrough. The frictional adjustment of the unit 42| is obtained by an adjusting or friction screw 425 which is threadably adjustable on the control shaft 4l4,

and enga-geable with the end 430 of the unit 42l. -It is readily apparent, therefore, that a loosening of the nut 42.5 serves` to open the ring assembly 402 to removelfthefrictional engaging-pretssure from the control rings 416 without in any manner affecting the assembly of the hub portions 411 and separating discs 4|8 on the control shaft 4|4. Conversely a tightening of the nut 425 serves to frictionally lock the control rings in their adjusted positions and hence in a fixed position relative to the control shaft 4| 4. A spring washer or disc 4Z0 (Figs. 1 and 3) is mounted about the shaft 4|4 and between the gear 4H! and side plate 404 to substantially eliminate axial movement of the shaft or any of the parts arranged thereon. v

Cooperating with each ring 416 is a corresponding latch 424 (Figs. 2 and 4). Each latch is pivotally supported on a pivot member 426. The pivot members are angularly spaced about the control ring assembly 402 and are mounted in the side plates 403 and 404. The tip portion 421 on each latch is pivotally movable into and out of the recess 408 on its associated control ring. Substantially adjacent each tip portion 421 is a slot 428, open at one end, for engaging a flat spring 423 of angular shape but having a straight portion for seating on an armature member 43| (Fig. 1). together by a rivet 432 or other like means. One end 433 of the spring 429 extends through the armature and side plate 403 and downwardly, as viewed in Fig. l, for engagement with an insulating back plate 434 which may be formed as part of a tuning indicating dial 435. The opposite end of the spring extends through an open ing 431 formed on the side plate 404, the size of the opening limiting the radial movement of the spring and in turn the latch 424 relative to the control ring 4| 6, as will be explained. The armature 43| also extends through the side plate 403 and is pivotally supported therein, the end portion 438 of the armature being bent in a direction opposite to the spring end 433 and in engagement with the insulating plate 434.

As is readily apparent from Fig. l, engagement of the spring end 433 with the member 434 serves to tension the spring 429 in a manner to always urge the armature to its open position with reference to its associated Ymagnet 439. This open position of the armature is defined by the engagement of the spring end 440 with the upper edge of the slot 431 in the plate 404 and is such as to permit a complete separation of a latch 424 from its corresponding control ring. The flexible connection of the latch 424 and the armature 43|, as accomplished by the spring 424, provides for the armature 43| being pulled securely against the magnet pole tips 44| whenever the magnet 439 is energized. Immediately on energization of the magnet 430, therefore, the armature is pulled to its closed position regardless of whether or not the latch tip 421 is in the ring notch 408 or on the periphery cf the ring. This structure provides for a quiet operation of the latch with alternating current magnets. It is to be noted also that the latch 424, by virtue of the spring 429, is frictionally engaged with its corresponding ring immediately on energization of its associated magnet.

A slip clutch may be arranged between the driving gear 400 and motor shaft 405 to cushion the blow which occurs when the latch tip 421 engages the recess 408 to stop and position the mechanism at the desired frequency.

The magnets 439 are angularly spaced about the control shaft 4| 4 and substantially within the peripheral confines of the control rings 4| 6, with each magnet being mounted on` ayoke member Ihe spring and armature are secured 442 which in turn is mounted on the side plate 403. The gap adjustment between the armature 43| and the magnet pole tips 44| is accomplished by means of the yoke securing screws 443, adjustment of these screws serving to move the magnet radially relative to the armature 43|.

end of a collar or sleeve member 448 which is mounted on the shaft 4|4 and attached thereto by a set screw 449 or like means. A cam 45| for actuating a switch 452, to be explained, is secured to the opposite end of the collar 448. Cam 446 is associated with a follower element 453 which is rotatably supported at one end of a crank arm 454, the opposite end of the arm being mounted on the condenser shaft 456, which is rotatably supported in a supplementary frame structure 451. Engagement of the follower and the cam is accomplished by a, spiral spring 458 which is connected at one end to the shaft456 and at its opposite end to the frame 451 so as to be tensioned in a manner to always urge the follower against the cam.

In one commercial adaptation of my invention, the cam 446 and crank arm assembly 441 are arranged to rotate the condenser 444 through a complete tuning range for only about an degree rotation of the control shaft 4l4. This degree of rotation occurs substantially over the cam portion indicated between the lines A-A in Fig. 5, the relative arrangement of the cam and the condenser being such that the condenser during this rotation of the cam 446 is actuated from its closed position to its open or starting position. The remaining 280 degrees of cam rotation is utilized to rotate the condenser from its open to its closed position. Since the motor 40| is of uni-directional type, it is contemplated that the eifectiv'e tuning function of the condenser occur during the 280 degree angular rotation of the cam. In other words, the cam 446 is designed so that the condenser will be closed during a 280 degree travel of the cam 446 or shaft 4 I4 and will be opened during the additional 80 degrees required for a full 360 degree rotation of the cam. Any other form of tuner which might be operated from a uni-directional rotating shaft vobviously may be substituted for the condenser 444.

The operation of my electric tuner will be more clear from a consideration of the circuit diagram of Fig. 7. Power is delivered to the circuit from a suitable source, indicated at 46|, a master switch 462 for the radio receiver being arranged in the supply lead 463. The circuit includes a series of push buttons 464, which, as shown in Figs. 1 and 2, may be mounted on the side plate 403. It is to be understood, of course, that the the push buttons may also be located remotely from the radio receiver. On pushing of a button 464 to energize a magnet 43S, the motor 44| is simultaneously energized through a circuit which comprises the common magnet lead 466, conductor 461, return lead 468 and the secondary winding 469, the motor being arranged so as to be in series connection with all of the magnets.

Rotation of the motor rotates the ring assembly tionv of the magnet-439,rotation of the ring assembly continues until the latch tip 421 is seated in the recess 408 of the control ring. During the tuning operation, the radio receiveris muted so that undesirable noises which would normally be reproduced in the speaker are eliminated.

The muting circuit, which is indicated generally at 414, operates to perform two functions. Its rst function occurs whenever a tuning button is pressed, the potentials derived from the winding of motor 49| through conductor 411 being recti ed and applied to the grid of tube 414. Its second function occurs whenever the receiver is automatically turned off by action of the switch 452, in which case a potential developed across resistor 492 is applied through lead 419 to overbias the tube 414. Resistor 482 provides normal bias to the tube 414 and during normal operation resistor 492 is shorted by the lead 483, contacts 41| and 412 and ground connections 484 and 49|.

The heater circuit includes a secondary winding 486, conductors 481 and 488, and contacts 412 and 413. A usual B circuit including secondary Winding 415 is indicated at 416. Switch contacts 41|, 412, 413 are all closed throughout the 280 degree travel of the cam 446 but are opened in the center of the remaining 8O degrees of its travel by the cam 45|, thus automatically opening the heater circuit and muting the set. Since the condenser is moved from its closed to its open or starting position during the 80-degree rotation of the cam 446, the contacts of the relay switch 452 are permitted to be opened by the low portion 489 on the actuating cam 45| during such angle of rotation. The opening of contacts 412 and 413 serves to open the tube heating circuit and the opening of contacts 413 and 41| actuates the muting circuit. The actuation of the muting circuit continues as long as the spring contact 413 engages the low portion 489 of cam 45|. On the return of the condenser to its starting position the relay switch 452 is returned to its closed position, so that the radio set is again operable to play on tuning of the condenser.

It is thus seen that the switch 452 is opened substantially only during the time the condenser is being rotated from its closed position to its open or starting position. That is, the recess or low spot 489 on the cam 45| is arranged relative to the condenser actuating cam 445 to engage the switch 452 only when the condenser is being returned to its starting position by the 80 degree rotation of the cam 446, as was above fully described. It is apparent, therefore, that an automatic turning olf of the set may be accomplished by allocating one of the magnets 439 and associated latch and control ring, to stop the ring assembly 482 when the contact arm 413 is on the low spot 489 of the cam 45|.

In the event a clock mechanism is desired for operating the tuner, a clock 493 may be connected across the leads 463 and 494 and arranged to remain in operation irrespective of the position of the master control switch 452. A cam switch |82 provided on the clock mechanism is designed to close at equal intervals of time. A plurality of conductors |83 are likewise provided on the clock-mechanism and spaced so that an arm (not shown) series connected with the switch |82 and having one end movable by the clock-mechanism engages a conductor |83 during each time interval. A circuit is thus extended from the particular conductor |83, through the movable arm and cam switch |82 to the conductor 456. The conductors |83, in turn, are adapted to be interconnected with electric tuner leads |86 by slidable contacts |84.

Before the control unit 482 is operated for tuning purposes as above explained, all of the control rings 4|6 are set in predetermined angular positions corresponding to the tuning positions of the condenser 444 for each of the desired stations. Assuming that the adjusting screw 425 and fric- 'tion unit 42| are in a non-friction position relative to each other, a selected latch 424 is actuated into engagement with its corresponding control ring by inserting a screw driver or the like through an aperture 450 in the plates 434 and 436 and pressing the armature portion 438 t0 move the armature toward its closed position. The operator first rotates the control shaft 4| 2 until the latch drops into its notch on the tuning ring 4|6, and then rotates the control shaft 4|2, and in turn rotates the condenser 444, relative to the held ring 4 I6 until the condenser is at a position corresponding to the signal frequency desired. This position can be ascertained by listening to the station and by observing the dial scale 436 and pointer 436 attached to the sleeve 42|. When this-position of the condenser 444 is obtained the latch is released by removing the screw driver and releasing the armature extensions 438. This same procedure is followed for each of the control rings 4|5, and with each ring separated from each other in the control asembly 492 by the axially yieldable but angularly xed separators 4|8, there is no possibility of any relative movement between a control ring 4|6 and the shaft 4|4 so as to cause any displacement of the control rings previously set. When the setting operation for the rings 4|6 is completed the clamping screw 425 is tightened to frictionally engage the unit 42| which in turn frictionally engages and clamps the rings 4|6 in fixed positions relative to the control shaft 4I4.

From a consideration of the above description it is seen that my invention provides an electric tuner which is very compact, and of a preassembled construction so as to have wide flexibility l in application to a large variety of tuning adaptations. The electric tuner is fast and accurate in operation, and is capable of operating quietly and smoothly over a long service life with a minimum of adjustments and maintenance service. The magnet structures used are of a similar construction and of the same size whereby to eliminate any plurality of magnet designs. A single standard magnet is thus utilized which is relatively assembled with its cooperating mechanism to perform eliciently on either A. C. 'or D. C. operation. Also the control rings 4|8, hub members 4|1, separating discs 4|8, and latches 424 are all adapted to be formed by a simple stamping operation from a suitable sheet material so as to appreciably reduce the overall cost of the unit and extend its application to radio receivers in the popular price class.

Although I have illustrated and described my invention with reference to a particular embodiment, it is to be understood that modications and alterations can be made therein which are within the full intended scope of my invention as defined by the appended claims.

I claim:

1. Control apparatus for an adjustable device, said apparatus including a shaft connected with said adjustable device to move the same to a plurality of predetermined control positions, a plurality of control rings stacked on said shaft, means for exerting a clamping force on said stack of rings in a direction extending axially of said shaft, thereby to clamp said rings in predetermined positions relative to said shaft, each of said control rings having a stop portion on the periphery thereof, a latch for each control ring having a portion movable into engagement with a corresponding stop portion to denne a control position of said adjustable device, magnet means individual to each latch to operate the same, said magnet means being positioned about said rotary shaft substantially within the peripheral connes of said control rings, a motor foi` rotating said shaft, and means for selectively operating said magnet means concurrently with an operation of said motor.

2. In an electrical tuning device for operating the variable tuning means of .a radio apparatus and provided with frame means including a pair of wall members, a rotary control shaft for moving said tuning means to a plurality of predetermined tuning positions, said shaft being rotatably mounted in said wall members, a plurality of control rings axially mounted on said shaft between said wall members, each of said control rings having a recess in the peripheral edge thereof. a plurality of pivoted latches corresponding to said control rings, each of said latches having a stop portion movable into engagement with a corresponding recess, pivot members corresponding to said latches and mounted on one of Said wall members, operating magnets corresponding to said latches mounted on said one of said wall members between said two wall members, a motor for driving said control shaft arranged interme-` diate said wall members, and means for selectively actuating said magnets, with engagement of a selected latch with the recess of a corresponding control ring defining one of said predetermined tuning positions.

3. In a tuning devi-ce having variable tuning means, a rotary control shaft for moving said variable tuning means to .predetermined tuning positions, a plurality of angularly adjustable control rings mounted on said shaft, with each ring having a stop recess, in the periphery thereof, a plurality of pivoted latches corresponding to said control rings, with each latch havin?, 'a stop portion at one end thereof, magnet means for each latch including -a pivoted armature, means operatively connecting each armature |with its corresponding latch, means for selectively actuating said magnet means to pivot a selected latch into engagement with a corresponding control ring, a uni-directional motor for `driving said control shaft, and cam means operatively connecting said control shaft and tuning means and operable to move the tuning means in reversed directions, with the seating of the stop portion of a selected latch in the stop recess of a corresponding control ring defining one of said predetermined tuning positions.

4. An electrical control device for controllable apparatus including a rotary shaft for moving said controllable apparatus to a plurality of predetermined control positions, a control ring of flat annular form, with a plurality of said control rings being stacked on said control shaft and each control ring havingr a stop portion. in the periphery thereof, a flat separating member between ad'acent control rings extended beyond -the peripheral margins of said control rings, a

latch corresponding to each control ring having a Aportion extended between adjacent ones of said separating members and movable into engagea. 'control position, said latches being angularly spaced about said control rings, magnet means individual to each latch to operate a corresponding movable portion, and means for selectively operating said magnet means.

5. In a preselector device having a control shaft for moving controllable apparatus to preselected control positions, a two piece control unit of nat form corresponding-to a control position of Said controllable apparatus and adapted to be formed from a single piece of sheet metal, with a plurality of said control units being stacked on said oontrol shaft and each thereof comprising a control ring angularly adjustable about a corresponding hub portion which is retained against rotation relative to said shaft, a at separator member between adjacent control units rotatable with; said shaft but having a portion thereof between adjacent control rings exible axially of said shaft to permit an independent rotation of each control ring to an adjusted position, and means for clamping said separator member portions and control rings together to prevent relative rotation between said control rings and control shaft.

6. In a tuning device having frequency changing means, a rotary control shaft for moving said frequency changing means to predetermined tuning positions, a plurality of two piece control units .in a stacked relation on said control shaft,v each of said control units being of a flat form and including a sheet metal control ring angularly adjustable about a corresponding sheet metalv hub portion, separating means of at form intermediate each pair of control units providing for an independent rotation 4of each of said control rings to an adjustable position, and means for clamping said control rings in adjusted positions for rotation with said shaft. r

7. An electric control device for controllable apparatus including a rotary shaft for moving said controllable apparatus to a plurality of control positions, a plurality of control rings stacked on said rotary shaft, with each of said control rings having a stop portion on the periphery thereof and being of a flat form so as to occupy a minimum of space axially of said rotary shaft, a pivoted latch for each control ring having a portion movable into engagement with a corre-- sponding stop portion to define a control position, means pivotally supporting said latches in an angularly spaced relation about said control rings, magnet means for each latch including an armature for operating a corresponding latch, said magnet means being angularly spaced about said shaft substantially within the peripheral connes of said 'control rings, spring means connecting an armature and a corresponding latch to resiliently urge said latchinto engagement with a corresponding control ring on operation of a corresponding magnet means, a motor for rotating said shaft, and means selectively operating said magnet means concurrently with an operation of said motor.

8. In a tuning device having frequency changing means, a rotary control shaft for moving said frequency changing means to predetermined tuning positions, a plurality of two-piece stamped-meta] hub portions and control ring assemblies stacked axially on said shaft, with said hub portions being mounted on said shaft and said control rings being angularly movable about "a corresponding hub portion, a flat separator member of larger diameter than said hub portions located intermediate adjacent ones of said two-piece assemblies, means for securing said separator members and hub portions together' for rotation with said shaft, with` the peripheral portions ofv said separator members located radially outwardly from said hub portions acting to frictionally retain said control rings against free angular movement, and means acting on said peripheral portions and control rings to clamp the same together to provide for a rotation of said control rings with said control shaft,

9. In a tuning device having frequency changing means, a rotary control shaft for moving said frequency changing means to predetermined tuning positions, a plurality of two-piece control structures stacked on said control shaft, with each of said control structures including a control ring and a' corresponding hub portion formed from a similar sheetmaterial, with a hub portion being mounted on said shaft and within a corresponding control ring which is adjustably movable angularly about said hub portion, at separating means intermediate adjacent control structures, means retaining said hub portions and separating means against angular movement re1- ative to said control shaft, but permitting an axial flexing of the portion of said separating means intermediate adjacent control rings, said axial flexing providing forv an independent rotation of each of said control rings to an adjusted position, and means for clamping said control rings together for rotation with said control shaft.

10. In a tuning device having frequency changing means', a rotary control shaft for' moving said frequency vchanging means to predetermined tuning positions,- a plurality of flat control rings aligned axially of said control shaft, a hub portion for each control ring carried on said control shaft, with a control ring being rotatable about a corresponding hub portion, a separating portion intermediate adjacent control ring and hub assemblies, means securing said hub portions and separating members in xed positions relative to said control shaft, with the peripheral portion of a separating member located outwardly from the periphery of a hub portion frictionally retaining said control rings against free rotatable movenient, and means for clamping said control rings to rotate with said control shaft.

1l. In a preselector device having a control shaft for moving controllable apparatus to preselected control positions, a plurality of fiat control units of sheet metal construction stacked on said control shaft, flat separator members between adjacent control units, each of said control units being comprised of a hub portion xed relative to said shaft and an adjustable ring portion rotatable` about said hub portion, with said two portions being in a commonplane radially of s aid control shaft, and each of said separator members having a portion between adjacent hub portions in rigid connection with said shaft, and a portion between adjacent control rings free for flexing movement in a direction axially of said control shaft, and means for clamping said control rigs against rotation relative to said control shaft.

l2. iAn electric control apparatus for controllable apparatus including a rotary shaft for moving said controllable apparatus to aplurality of predetermined control positions, a plurality of control rings stacked on said rotary shaft with each of said control rings having a stop portion on the periphery thereof, means for stopping said shaft at a control position including a pivoted latch corresponding to' each control ring and movable into engagement with a corresponding stop portion, axis means for said latches angularly spaced about said shaft, magnet means correspending to said latches for operating the same ang-ularly disposed about said shaft, with a magnet means being intermediate adjacent axis means and substantially within the peripheral confines of said control rings, a motor for rotating said shaft, and means for selectively operating said magnet means substantially concurrently with an operation of said motor.

13. In an electrical tuning device having frequency changing means, a rotary shaft for moving said frequency changing means to a plurality of predetermined control positions1 a plurality of control rings stacked on said shaft' and rotatable relative thereto to an adjusted position, each of saidcontrol rings having a stop portion on the periphery thereof, a movable latch individual to each control ring and operable to engage a corresponding stop portion to denne a control position, magnet means individual to said latches and each having an armature for operating a corresponding latch, motor means for rotating said shaft, manual means for rotating said shaft independently of said motor means, a portion on each armature for manually moving the armature to operate a corresponding latch on rotation of said shaft by said manual means to adjust a control ring in a control position, and means for clamping said control rings in their adjusted positions for rotation with said shaft by said motor means.

14. A preassembled electric control device having a pair' of wall members and a rotary shaft, for moving controllable apparatus to preselected control positions, rotatably supported on said wall members, a plurality of angularly adjustable control rings stacked on said rotary shaft, each of said control rings being of a fiat form and having a. stop portion on the periphery thereof, with said stack being positioned adjacent one of said Wall members, pivoted latches corresponding to said control rings, with each latch being movable into engagement with the stop portion on a corresponding control ring to define a control position, axis means pivotally supporting said latches and carried in said wall members, magnet means corresponding to said latches for operating the same, said magnet means being supported in a position adjacent the other of said wall members and being disposed substantially within the peripheral connes of said control rings, and a motor for operating said rotary shaft located intermediate said wall members and supported thereon.

l5. In a tuning device for a radio receiver having a variable condenser, a rotary control shaft for moving said condenser to predetermined tuning positions, a plurality of angularly adjustable control rings mounted on said shaft, with each ring having a stop recess in the peripheral edge thereof, a plurality of pivoted latches corresponding to said control rings and angularly spaced about said shaft, with each latch having a stop portion at one end thereof, magnet means for each latch including a pivoted armature, spring means operatively connecting each armature with its corresponding latch, means for selectively actuating said magnet means to pivot a selected latch into engagement with a corresponding control ring, said spring means permitting movement of said armature to its full closed position irrespective of the engaged position of said selected latch with said corresponding control ring, ya uni-directional motor for driving said control shaft, said motor being in series connection with each of said magnet means, and cam means operatively connecting said control shaft and condenser and operable to move the condenser in reversed directions, With seating of the stop portion of the selected latch in the stop recess of a corresponding control ring dening one of said predetermined tuning positions and stopping rotation of said rotary control shaft,

16. In radio tuning apparatus having a rotatable variable condenser, a rotary control shaft for moving said condenser to a plurality of predetermined tuning positions, a, plurality of angularly adjustable control rings coaxially mounted on said shaft, with each ring having a stop recess in the periphery thereof, a plurality of pivoted latches corresponding to said control rings, with each latch having' a ystop portion formed near one end thereof, a pivot member for each latch arranged parallel to-said control shaft and angularly spaced about said control rings, magnet means in operative engagement with ,each of said latches, said magnet means being angularly spaced about said control shaft and substantially adjacent one end of said control rings, a motor for rotating said control shaft in one direction, means operatively connecting said shaft and `condenser and operable to reversely rotate the condenser between its open and closed positions, and means for selectively actuating said magnet means to pivotally move a selected latch into engagement with its corresponding control ring, with seating of said latch stop portion in said stop recess defining a predetermined tuning position of said condenser and stopping the rotation of said control shaft, said motor being in series connection with each of said magnet means. i

17. In an electrical tuning device for operating the variable tuning means of a radio receiver and provided with frame means including a pair of Wall members, a rotary control shaft for moving said condenser to a plurality of predetermined tuning positions, said shaft being rotatably mounted in said Wall members, a plurality of control rings coaxially mounted on said shaft and between said wall members, each of said control rings having a stop recess in the peripheral edge thereof, a plurality of pivoted latches corresponding to said control rings, each latch having a stop portion formed near one end thereof, pivot members corresponding to said latches mounted in said Wall members and angularly spaced about said control rings, operating magnets correspond ing to said latches mounted on one of said wall members and angularly spaced about said shaft,

armatures corresponding to said magnets and pivotally supported in said one Wall member, a motor for driving said control .shaft arranged intermediate said Wall members, and means for selectively actuating said magnets, with engagement of the stop portion of a selected latch in the stop recess of a corresponding control ring dening one Iof said predetermined condenser tuning positions and stopping rotation of said control shaft.

1 8. In a control device, a rotary control shaft, a plurality of two-piece control units arranged in stacked relation on said shaft, each of said units including a thin inner supporting member rotatable with said shaft and a thin control ring adjustable about the associated inner supporting member,l thin separators intermediate each pair of control units and providing for an independent rotation of each of said control rings to an adjusted position, and meansl for clamping said control rings in adjusted positions relative to said shaft.

19. In a control device, a rotary control shaft, a plurality of two-piece control units arranged in stacked relation on said shaft, each of said units including a thin inner supporting member rotatable With said shaft and a thin control ring adjustable about the associated inner supporting member, thin separators intermediate each pair of control units and providing for an independent rotation of each of said control rings to an adjusted position, each of said separators being of greater diameter than the other diameter of said control rings such that a guide channel is provided around the outer periphery of each control r'ing, and means for clamping said control 'rings in adjusted positions relative to said shaft.

HAROLD F. ELLIOTT. 

